1. Field of the Invention
The present invention relates generally to systems for the filling, transport, and emptying of liquid containers More particularly, the invention concerns a novel, corrosion resistant liquid extraction apparatus that includes a novel plastic valve that can be removably connected to a liquid transport container. In turn, the valve can be interconnected with a specially configured, corrosion-resistant, plastic coupler that operates the valve in a manner to enable fluid to be extracted from the container.
2. Discussion of the Prior Art
The storage and transport of liquids and particularly the storage and transport of hazardous liquids have long presented substantial problems. For many years liquids were stored and transported in throwaway type metal and plastic containers. Typically, such containers were provided with a threaded liquid outlet port, which, after the container was filled, was closed, by some type of threaded cap. The use of these types of containers was costly, inefficient and often hazardous, particularly when the containers were used to store and transport potentially dangerous chemicals.
In recent years substantial efforts have been made to develop new systems to improve container and drum management capabilities, minimize user exposure to hazardous materials and address emerging governmental regulations. These efforts have resulted in the development of several different types of reusable systems for transferring liquid formulations from returnable closed drums and containers. As a general rule, these systems to a greater, or lesser extent, simplify drum emptying, minimize operator hazards, improve cleanliness and eliminate costly waste inherent in prior art disposable container systems. One of the most advanced of such improved systems was developed by and is presently commercially available from Micro Matic, Inc. of Northridge, Calif.
The Micro Matic system, which is described in U.S. Pat. No. 5,901,747 issued to the present inventor, basically comprises a two-part system that includes a coupler operated extractor valve which can be interconnected with a conventional drum via existing threaded connections and a cooperating coupler which connects to the extractor valve to allow drum emptying through the use of a remote pumping system. The extractor valve apparatus includes a valve body and a down tube connected to the valve body, which extends to the bottom of the drum to permit the complete transfer of liquid from the drum.
Another Micro Matic prior art liquid transfer system is described in U.S. Pat. No. 5,944,229 also issued to the present inventor. This invention concerns a novel, tamper-proof, safety valve system that includes a tamper evident valve closure cap that must be broken before liquid can be removed from the container.
The Micro Matic systems, while representing the best of the current state of the art liquid transfer systems, have certain drawbacks which are sought to be overcome by the system of the present invention More particularly, the metal valve and coupler assemblies of the Micro Matic systems are of a relatively complex design making them somewhat difficult and costly fabricate. Further, in some respects these metal assemblies are not well suited for use with various types of hazardous and highly corrosive chemicals that are frequently stored and transported.
As will be better appreciated from the discussion that follows, unlike the prior art Micro Matic systems, the novel valve and coupler of the improved system of the present invention are of an elegantly simple design and are uniquely constructed from a corrosive resistant plastic that is substantially impervious to most corrosive liquids. Additionally, the improved system provides a customer unique, key type coupler-valve mating interface that precludes removal of the drum contents by unauthorized persons